<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div{
            background: plum;
            height: 200px;
            width: 200px;
            margin: 10px 20px 30px 40px;
        }
    </style>
</head>
<body>
    <h1>外边距：元素与元素之间的距离</h1>
    <div></div>
    <div></div>
</body>
</html>